1. Field
This invention relates to adjustable bicycle seats. More particularly it relates to an adjustable bicycle seat hydraulically cushioned to absorb shocks during riding.
2. State of the Art
A number of bicycle seat adjustable height and shock absorbing systems are known. Zurfluh et al., U.S. Pat. No. 5,713,555 discloses a saddle support for a bicycle employing a gas cylinder and piston attached to the saddle to adjust the height of the saddle during riding. The gas cylinder elevates the piston during riding, which is then clamped into position to secure the saddle at a variable height. Once clamped, the compressed gas cylinder acts as a shock absorber to cushion the ride. Unfortunately, the more the piston is extended, the softer the ride as the gas volume increases resulting in reduced pressure resistance inside the gas cylinder. Becker, U.S. Pat. No. 5,829,733 discloses another adjustable height shock absorbing bicycle mounting assembly employing a gas spring system.
DeFreitas, U.S. Pat. No. 5,826,935 discloses another automatic bicycle seat adjuster for adjusting a bicycle seat's height while riding via a gas cylinder and spring system. This system sets the height of the bicycle, and uses a spring system to provide for a softer ride. Voigt, U.S. Pat. No. 5,383,705 provides a spring cushioned shock absorbing bicycle seat system. Massaro, U.S. Pat. No. 5,324,058 discloses a combination spring/fluid bath bicycle seat shock absorbing system mounted within the bicycle seat frame to cushion the ride. The ride is adjusted by varying the compression tension of the spring. Hartway, U.S. Pat. No. 5,094,424 discloses a bicycle seat post shock absorber assembly employing tubular mounted coil springs.
Cited for general interest are: Hale, U.S. Pat. No. 3,339,873 disclosing a stool with vertically movable seat employing a reciprocal piston rod containing air under pressure from a pressure tank to control the ascent and descent of the seat. Hale, U.S. Pat. No. 3,636,816 discloses a power unit mounted within the vertical post of a stool using a reservoir containing oil under pressure of compressed air which can be used to change the effective length of the seat.